William piguet



Patented Aug. 2, 1892.

W. PIGUET.

(No Model.)

STOP WATCH.

lilNiTnn STATES pATFNT @FFIQFZQ VILLIAM PIGUET, OF SENTIER, SIYITZERLAND.

. STOP-WATCH.

SPECIFICATION forming part of Letters Patent No. 479,900, dated August 2, 1892.

Application filed December 8, 1891. Serial No, 414,431. (No model.)

To a/ZZ whom t may concern;

Be it known th at I, IVILLIAM PIGUET, watchmanufacturer, of Sentier, Switzerland, have invented an Improvement in Stop-Watches, of which the following is a specification.

This improvement relates to that class of watches in which there is a main secondshand that is constantly rotated and another seconds-hand which may rotate with the main seconds-hand or be stopped when an observation is to be made, or it may be returned to the normal position and caused to rotate with the main seconds hand. In this class of watches the axis carrying the constantly-rotating main seconds-hand has been provided with a heart-cam against which a spring-lever acted to cause the two hands to rotate together, and when the independent secondshand was stopped the friction of the lever upon the cam interfered with the proper rotation of the main seconds-hand.

By the present invention a mechanism is brought into action to swing back the springlever from contact with the heart-cam simultaneously with the stopping of the independent seconds-hand, thus preventing any friction against the heart-cani of the main seconds-hand, leaving such main seconds-hand to rotate nnobstructedly.

In the drawings, Figure l represents the improved mechanism with the face of the watch removed, showing only a portion of the watch-plate. Fig. 2 is a section at the linea: a: and on a magnified scale. Fig. 3 is an inverted plan view showing the heart-cam and the wheels surrounding the arbors of the seconds-hands in the same size as shown in Fig. 2, and Fig. 4L represents the rack in aslightlymodified form.

The arbor V of the main seconds-hand Y is acted upon by any suitable mechanism, so as to be revolved once in a minute, and upon this arbor Y the heartcani II is iirmly fastened.

The stop-wheel B surrounds the arbor V and has a tubular axis b for the independent seconds-hand X, such tubular axis Z2 revolving freely upon the arbor V, and around the tubular axis'b is a ratchet-wheel C, which is free to turn on such tubular asis b, but it is held in position by acollar c. Upon the stopwheel B is a lever D, acted upon by a spring G to press the moving end of said lever D against the heart-cam II, asillustrated in Fig. 3, and there may be a jewel E at this end of the lever D, and thehands X and Y coincide when the lever D is in its normal position against the heart-cani II, as seen in Fig. 3. IIence the two hands X and Y revolve in unison under ordinary circumstances and there is little or no unusual friction.

Upon the ratchet-wheel C is a pin c', that proj eets through the wheel I3 and is adjacent to the lever D, as seen in Fig. 3, and upon reference to the dotted lines in this Fig. 3 it will be observed that if the wheel B is held stationary and the wheels C moved in the direction of the arrow the pin c swings the lever D out of contact with the heart-cam H and into the position indicated by dotted lines. This operation is effected by the devices hereinafter described, and when this movement is effected t-he wheel B and the hand X are held stationary and the arbor Y, heart-cam Il, and hand Y are free to revolve without undue friction and without any disturbing influence. I make use of a push-piece N2 at the end of a lever N, that is pivoted at N and acted upon by a spring O and provided With a pawl P, pivoted at p and having a spring Q to aetuate the ratchet-wheel L, as in ordinary stop-watches, and there is a spring M with a double inclined end that acts as a pawl to hold the ratchet-wheel L in the position to which it may be moved, and beneath and connected with the ratchet-wheel L is a cam-wheel L', that acts upon the stopping and starting devices.

The spring-clamps I and I2 are fastened at one end to the watch-plate, and their other ends are nearly semicireular, so as to be adapted to grasping the stop-wheel B, and it is advantageous to have the edges of this stopwheel made with fine teeth or roughened, so as to hold this stop-wheel B firmly by the spring-clamps I I2, and there isa Wedge-lever K, pivoted at K and with its Wedge-shaped ends between the offsets or shoulders of the spring-clamps I I2. I-Ience when one tooth of the cam-wheel L presses the wedge of the lever K in between the shoulders of the springclamps I I2, as seen in Fig. 1, such clamps are moved away from the wheel B, so that the latter may revolve freely, and when the IOO tooth of vthe cam-wheel L passes away from the back ot' the wedge on the lever K, the spring-clamps I I2 are free to close against the Wheel B and hold the same iirmly.

In order to give motion to the ratchet-wheel C simultaneously with the grasping of the Wheel B by the spring-clamps I l2, a rack T is made use of, the teeth of which engage the teeth of the wheel C and give to the lattera partial rotation tomove the pin c and swing the lever D, as before mentioned. This rack T is upon the lever R, pivoted at R and acted upon in one direction by the spring S and in the other direction by the teeth of the caniwheel L, as seen in Fig. 4, and this lever R and rack T may bellin one piece, as shown in Fig. 4f, or they may be joined together, as shown in Fig. l, there being a joint T with a spring T5, acting against a pin T6, to throw the teeth of the rack T toward the Wheel C; but when in the position shown in Fig. l the pin T4 in the plate of the Watch has acted against an offset upon the rack near the joint T to throw the rack away from the ratchet- Wheel C and separate the teeth thereof.

In Fig. 4 the same object is accomplished by the movement given to the lever R being su tticient to carry the teeth of the rack beyond and free from the teeth of the Wheel O. The operation of these devices is that when the 1ever N is moved by the push-piece N2 and the pawl P moves the ratchet-wheel L and camwheel L from the position shown in Fig. lthe teeth of L pass clear of the projections on the levers K and R and the wedge of the leverK is moved back from the spring-clamps I I2 by the spring of said clamps, and these clamps grasp the wheel B, and as a tooth of the camwheel L clears the projection on the lever R the spring S gives to said lever a movement which causes the teeth of the rack T to turn the wheel C sufficiently for its pin c to raise the lever D from contact with the heart-cam H, and in this position the hand X is held irmly, while the hand Y continues to rotate unobstructedly. When the lever N is again moved by the push N2 and the WheelLInoved by the pawl P the extent of another tooth, the teeth of the cam-Wheel L again return the parts to the position indicated in Fig. l, and 5o in so doing the rackT moves the wheelCback to its normal position and the pin c allows the lever D to act against the heart-cam H and return the hand X to unison with Y, so that they revolve together, and the spring-clamps I2 are simultaneously opened, so that there is no obstruction to the free rotation of the Wheel B.

I claim as my inventionl.. The combination, with the main and independent secondshands,of an arbor carrying the main seconds-hand, a tubular arbor surrounding the same, carrying` the independent seconds-hand, and a stop-wheel connected with the tubular arbor, a heart-cam upon the arbor of the main seconds-hand, and a springlever on the stop-wheel acting against the heart-cam, a wheel surrounding the arbor of the independent seconds-hand, and a pin acting upon the leverotn the heart-cam, and mechanism, substantially as specified, for holding the stop-wheel and independent seconds-hand and for moving the wheel and pin to separate the spring-lever from the heart-cam, substantially as set forth.

2. The combination, with themain and independent seconds-hands and their arbors, of a heart-cam on the arbor of the main secondshand, a stop-wheel connected with the arbor of the independent seconds-hand, a spring-lever upon the stop-wheel acting against the heart-cam, a ratchet-wheel surrounding the arbor of the independent seconds-hand, and a pin on the same to act upon the heart-canilever, spring-clamps for acting upon the stop- Wheel, a wedge-lever for opening the springclamps, a ratchet and lever for acting upon the ratchet-wheel and pin, and a push mechanism, ratchet-wheel, and cam-Wheel for acting upon the Wedge-lever and the ratchet-lever, respectively, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

WILLIAM PIGUET.

Vitnesses:

G. FRIED. SCHNEIDER, E. PRENTICE NAYLoR. 

